Textile treatment



United States Patent 3,493,320 TEXTILE TREATMENT John William Case andWilfred Arthur Stephen White,

Ruucorn, England, assignors to Imperial Chemical Industries Limited,London, England, a corporation of Great Britain No Drawing. Filed Nov.4, 1966, Ser. No. 591,989 Claims priority, application Great Britain,Nov. 9, 1965, 34,007/65 Int. Cl. D06] 1/02 U.S. Cl. S-137 12 ClaimsABSTRACT OF THE DISCLOSURE There is provided an improvement in theprocess of scouring textile materials with halogenated solvents whereinthe textile is enclosed in a vessel and the halogenated solvent iscirculated through the textile material. Suitably the textile is carriedon a perforated hollow mandrel which is closed at one end and which ismounted within the vessel. Optionally the solvent is circulated throughthe mandrel and then through the textile material, but the direction ofcirculation may be reversed. After solvent scouring the textile isrinsed, preferably with warm water.

This invention relates to a textile treatment process, and moreparticularly to a process for the scouring of textile materials.

It is known to remove oily and greasy matter from textile materials byscouring with aqueous alkaline solutions or by extraction with organicsolvents, particularly chlorinated hydrocarbon solvents. This latterprocess may be termed solvent-scouring.

Among the various techniques available for the treatment of texitlematerials, there is the so-called beam dyeing method. This involvesplacing a hollow mass of textile material (e.g. a roll of cloth or aspool of wound yarn) in a closed vessel and circulating a liquid throughthe mass either towards the centre or outwards from the centre. Theliquid used may be an aqueous dye-liquor or an aqueous scouringsolution.

We have now found that this beam dyeing technique can be used toachieved scouring of textile materials by means of organic solvents.According to the present invention we provide a process for scouringtextile materials which comprises enclosing the textile material in avessel and circulating an organic solvent through the textile material.

The textile material which may be any natural or synthetic textilematerial, including for example cotton, wool, nylon, polyester,cellulose acetates or mixtures thereof, may be conveniently in woven,knitted, or yarn form, but alternative forms such as carded webs may betreated. The material may be made up into any hollow form (e.g. rolls,spools or bobbins) which permits liquid to be circulated through it. Thecirculation is usually effected by way of a hollow perforated tube whichis closed at one end and which is positioned within the textilematerial, and through which the liquid can be fed in or drawn out.

The organic solvent can be used at room temperature or at an elevatedtemperature for example up to the boiling point, depending upon theparticular solvent and textile material employed, but in order tominimise the risks of sudden variations in pressure, care should betaken when hot solvent and water are together within the vessel. Forexample, if the textile material contains any natural moisture (and mosttextile materials do unless they are specially and rigorously dried)contact with hot 3,493,329 Patented Feb. 3, 1970 solvent will cause asudden range of vapours to form. Accordingly, We prefer to pump the hotsolvent so that it flows outwards first, until the water content of thetextile material has been vaporised and removed from the system, andafter that the direction of flow of the solvent can be in eitherdirection, or in alternate directions, as desired. Similar precautionsand direction of flow should be employed when subsequently displacingthe solvent from the textile materials by contact with hot water orsteam. A convenient procedure in this case comprises introducing thewater at a temperature of from room temperature to about 60 C., butpreferably not greater than C., and to raise the temperature of thewater during its circulating to C. to C., for example by including aheat exchanger in the circulating system.

The apparatus used can be any conventional form of beam-dyeingapparatus, the materials of construction being chosen to minimisecorrosion risks. Such apparatus will normally incorporate a pressurerelief valve. In addition, for economic and safe working, the apparatuswill usually be provided with a vapour duct of sufficient capacity tolead off solvent/water vapour mixtures from the vessel to a condensersystem in which the solvent is recovered; this should also incorporateconventional devices such as a distillation unit for separating solventliquid from water so that the solvent can be recovered for re-use.

During use of the apparatus, the water/solvent vapour mixtures are ledoff to the condenser until no more Water is evolved, and then the systemcan be operated in the same way as conventional beam-dyeing apparatus,the solvent being circulated through the textile material as long as isrequired. Following the main solvent treatment, a rinsing treatment withclean solvent may be employed.

The organic solvent may be in particular a chlorinated hydrocarbonsolvent, for example trichloroethylene or perchloroethylene, or achlorofluoro-hydrocarbon for example1:1:2-trichloro-1a2z2-trifiuoroethane. Mixtures of organic solvents maybe employed.

The particular solvent and operating temperatures may be chosen to suitthe particular textile material concerned, and to avoid any damage toit. The solvent treatment can conveniently be carried out at roomtemperature, and the solvent can be removed by a subsequent treatmentwith warm or hot water, or steam, to flash off the solvent.

The invention is illustrated by the following example.

EXAMPLE A sample of a cellulose acetate knitted fabric was wound on ahollow perforated mandrel having a closed end. The mandrel was thenenclosed in a conventional beam-dyeing machine adapted to circulatetrichloroethylene at room temperature. Tric'hloroethylene at roomtemperature was circulated through the fabric from the inside to theoutside for about 8 minutes. The resulting contaminatedtrichloroethylene was then withdrawn from the machine and was replacedby clean trichloroethylene, which was circulated through the fabric for2 minutes to rinse the fabric. This rinse liquor was then removed andwas replaced by water at 60 C. The water was circulated through a heatexchanger until the temperature within the vessel increased to 95 C. Thesolvent/water vapour mixture so formed was withdrawn to a condenser anddistillation system wherein the solvent was recovered for re-use. Whenthis temperature had been attained, the water was withdrawn from thevessel and the fabric was removed and examined. The fabric wassubstantially free from trichloroethylene.

A small weighed sample of the fabric was extracted with 1:1:2 trichloro2:2: 1 trifluoroethane for 4 hours in a Soxhlet extractor. The residue,after removal of entrained 1:1:2-trichloro-2z2: l-trifluoroethane wasweighed, and the percentage by Weight of contaminants (mainly wax) inthe fabric was then determined. For purposes of comparison a Weighedsample of the fabric prior to the treatment with trichloroethylene wasextracted as above to determine the percentage by weight of contaminantsin this sample. The results are shown in the table below.

The above procedure was then repeated five times except that thecellulose acetate fabric was replaced respectively by the followingknitted fabrics:

Expt. No.: Fabric 2 Polyester (Dacron). 3 Viscose rayon (Avril)55denier. 4 Nylonl5 denier. 5 Nylon-3O denier. 6 Nylon40 denier.

The results are shown in the table below:

TABLE Percent was content (untreated fabric) 2. 5 0. 04 0. J4 O. 09 2. 40. O5 0. 36 U. 05 1. O 0. 13 O. 5 0. 09

These results show that the various fabrics were effectively scoured bythe treatment.

What we claim is:

1. In a process for scouring textile materials with an organic solventselected from the group consisting of chlorinated and chlorofluorinatedlower hydrocarbons, the improvement which comprises enclosing thetextile material in a vessel and circulating the said organic solventthrough the textile material.

2. A process as claimed in claim 1 wherein the textile material iscarried on a perforated hollow mandrel which is closed at one end andwhich is mounted within the vessel.

3. A process as claimed in claim 1 wherein the treatment with organicsolvent is followed by a rinse 'with clean organic solvent.

4. A process as claimed in claim 1 wherein the organic solvent is usedat room temperature.

5. A process as claimed in claim 1 wherein water is circulated throughthe textile material subsequent to the treatment with organic solvent.

6. A process as claimed in claim 2 wherein the organic solvent isinitially circulated outwards from the mandrel through the textilematerial.

7. A process as claimed in claim 6 wherein the direction of circulationof the organic solvent is reversed at predetermined intervals of time.

8. A process as claimed in claim 3 wherein the organic solvent used torinse the textile material is the same as the organic solvent used inthe initial treatment.

9. A process as claimed in claim 5 wherein warm water is used.

10. A process as claimed in claim 9 wherein the temperature of the wateris not greater than C.

11. A process as claimed in claim 9 wherein the temperature of the wateris raised during circulation to C. to C.

12. A process as claimed in claim 11 wherein the temperature of thewater is raised by circulating the 'water through a heat exchangerincorporated in the system.

References Cited UNITED STATES PATENTS 3,404,943 10/1968 Morris 8142MAYER WEINBLATT, Primary Examiner U.S. Cl. X.R. 8-139, 139.1, 142

